Engines, whether gas turbine, gasoline, diesel, or hybrid, require a flow of air into the engine during operation. Some engines, particularly in aircraft, military, or high-performance vehicles, require an extremely high flow of air into the engine. Since particulates in the air can damage the engine, inertial separators (for example, vortex air cleaners, inlet particle separators (IPS), and engine air particle separators (EAPS)) are sometimes used with engines operating under conditions where the air may contain high volumes of particulates, to remove dirt from the air entering the engines. Inertial separators are particularly useful for use with aircraft, especially turbine driven aircraft (e.g., helicopters), as when close to the ground, they stir up great amounts of dirt and dust.
A plurality of inertial separators can be used with an engine, typically, each separator comprises a tubular body having a central passage with an inlet and an outlet at opposite ends, a deflector for creating a vortex stream in the influent air to concentrate contaminant particles in the air at the periphery of the passage and clean the air at the center of the passage, and an outlet member having a central clean air passage communicating with the central passage of the tubular body. The relatively clean air at the center of the passage passes through the central clean air passage of the outlet member. While some inertial separators operate with little or no scavenging, typically, the exterior wall of the outlet member defines a generally annular contaminant scavenge passage within the central passage of the tubular body, through which pass contaminant particles while relatively clean air at the center of the passage passes through the central clean air passage of the outlet member.
Some inertial separators have other applications, e.g., in industry, for example, to capture and/or separate particulates during woodworking, grinding, polishing, food processing, and painting.
However, inertial separators can be effective for undesirably short periods of time and/or expensive to produce and/or unable to withstand high operating temperatures.